title: Ambulatory consolidation chemotherapy for acute myeloid leukemia with antibacterial prophylaxis is associated with frequent bacteremia and the emergence of fluoroquinolone resistant E. Coli.
abstract: BACKGROUND
  Ambulatory consolidation chemotherapy for acute myeloid leukemia (AML) is frequently associated with bloodstream infections but the spectrum of bacterial pathogens in this setting has not been well-described.
  
  
  METHODS
  We evaluated the emergence of bacteremias and their respective antibiotic susceptibility patterns in AML patients receiving ambulatory-based consolidation therapy. Following achievement of complete remission, 207 patients received the first cycle (C1), and 195 the second cycle (C2), of consolidation on an ambulatory basis. Antimicrobial prophylaxis consisted of ciprofloxacin, amoxicillin and fluconazole.
  
  
  RESULTS
  There were significantly more positive blood cultures for E. coli in C2 as compared to C1 (10 vs. 1, p=0.0045); all E. coli strains for which susceptibility testing was performed demonstrated resistance to ciprofloxacin. In patients under age 60 there was a significantly higher rate of Streptococccus spp. bacteremia in C2 vs. C1; despite amoxicillin prophylaxis all Streptococcus isolates in C2 were sensitive to penicillin. Patients with Staphylococcus bacteremia in C1 had significantly higher rates of Staphylococcus bacteremia in C2 (p=0.009, OR=8.6).
  
  
  CONCLUSIONS
  For AML patients undergoing outpatient-based intensive consolidation chemotherapy with antibiotic prophylaxis, the second cycle is associated with higher rates of ciprofloxacin resistant E. coli, penicillin-sensitive Streptococcus bacteremias and recurrent Staphylococcus infections.
authors.affiliation: Department of Medical Oncology and Hematology, Princess Margaret Hospital, University of Toronto, 610 University Avenue, Rm. 5-109, Toronto, ON M5G 2M9, Canada.
authors.forename: Lalit
authors.initials: L
authors.lastname: Saini
authors.forename: Coleman
authors.initials: C
authors.lastname: Rostein
authors.forename: Eshetu G
authors.initials: EG
authors.lastname: Atenafu
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Brandwein
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D019072:Antibiotic Prophylaxis; D016470:Bacteremia / Q000382:microbiology*; D016009:Chi-Square Distribution; D060830:Consolidation Chemotherapy; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology*; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy* / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones